import java.util.Scanner;

public class Main2 {
    public static double func(int n) {
        int sum = 1;
        if (n > 1) {
            for (int i = 1; i < n; i++) {
                sum = sum * 2;
            }
            return sum-1+func(n-1);
        }
        return 0;
    }
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n= sc.nextInt();
        System.out.println(func(n));
    }
}